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DTC P1595-A: Speed Control Solenoid Circuits

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.
  1. Turn speed control (cruise control) on. Using scan tool, actuate speed control vent solenoid. If speed control servo clicks, go to next step. If speed control servo does not click, go to step  7.
  2. Scan tool should still be actuating speed control vent solenoid. Wiggle wiring harness between speed control servo, brake switch and Powertrain Control Module (PCM). If wiggling did not cause an interruption of speed control servo actuation, go to next step. If wiggling caused an interruption of speed control servo actuation, repair wiring harness as necessary where wiggling caused problem to appear. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  3. Using scan tool, actuate speed control vacuum solenoid. If speed control servo clicks, go to next step. If speed control vacuum solenoid does not click, go to step  7.
  4. Scan tool should still be actuating speed control vent solenoid. Wiggle wiring harness between speed control servo and brake switch to PCM while scan tool is still actuating speed control vacuum solenoid. If wiggling did not cause an interruption of speed control servo actuation, go to next step. If wiggling caused an interruption of speed control servo actuation, repair wiring harness as necessary where wiggling caused problem to appear. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  5. Condition to set trouble code is not present at this time. If SPEED CONTROL SOLENOID CIRCUITS DTC sets when PCM actuates vacuum and vent solenoids, but solenoids do not respond. Possible causes are: solenoid control circuit open or shorted, vacuum or vent solenoid shorted or open, open or shorted speed control power supply circuit or PCM failure. Go to next step.
  6. Inspect all related wiring and connectors and repair as necessary. If related wiring and connectors were repaired, perform TEST VER-4A: SPEED CONTROL VERIFICATION . If no problems were found with wiring and connectors, test is complete. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  7. Disconnect speed control servo 4-pin connector. DO NOT depress brake pedal during testing. Turn ignition on with engine off. Turn speed control switch on. Using a 12-volt test light, check voltage of brake switch output circuit at speed control servo 4-pin connector. See SPEED CONTROL SERVO CONNECTOR WIRE IDENTIFICATION  table. If test light is brightly illuminated, go to step  11. If test light is not brightly illuminated, go to next step.
  8. Turn ignition off. Using a DVOM, check resistance of brake switch output circuit between speed control servo 4-pin connector and ground. See SPEED CONTROL SERVO CONNECTOR WIRE IDENTIFICATION  table. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground on brake switch output circuit. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  9. Disconnect brake switch connector. Brake switch connector is located near top of brake pedal. Turn ignition on with engine off. Using a 12-volt test light, check voltage of speed control power supply circuit at brake switch connector. See BRAKE SWITCH CONNECTOR WIRE IDENTIFICATION  table. If test light is brightly illuminated, go to DTC P1595-B: SPEED CONTROL SOLENOID CIRCUITS . If test light is not brightly illuminated, go to next step.
  10. Turn ignition off. Disconnect Powertrain Control Module (PCM) connector. Using a DVOM, check resistance of speed control power supply circuit between brake switch connector and PCM connector terminal No. 5. See BRAKE SWITCH CONNECTOR WIRE IDENTIFICATION  table. If resistance is less than 5 ohms, replace PCM. Perform TEST VER-4A: SPEED CONTROL VERIFICATION . If resistance is 5 ohms or more, repair open speed control power supply circuit. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  11. Using a DVOM, check resistance of ground circuit between speed control servo 4-pin connector and ground. See SPEED CONTROL SERVO CONNECTOR WIRE IDENTIFICATION  table. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open ground circuit. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  12. Disconnect Powertrain Control Module (PCM) connectors. Using an ohmmeter, check resistance of speed control vacuum solenoid control circuit between speed control servo 4-pin connector and PCM connector terminal No. 56. See SPEED CONTROL SERVO CONNECTOR WIRE IDENTIFICATION  table and PCM CONNECTOR WIRE IDENTIFICATION  table. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open speed control vacuum solenoid control circuit. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  13. Using an ohmmeter, check resistance of speed control vent solenoid control circuit between PCM connector terminal No. 80 and speed control servo 4-pin connector. See SPEED CONTROL SERVO CONNECTOR WIRE IDENTIFICATION  table and PCM CONNECTOR WIRE IDENTIFICATION  table. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open speed control vent solenoid control circuit. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  14. Using an ohmmeter, check resistance of speed control vacuum solenoid control circuit between speed control servo 4-pin connector and ground. See SPEED CONTROL SERVO CONNECTOR WIRE IDENTIFICATION  table. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground on speed control vacuum solenoid control circuit. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
  15. Using an ohmmeter, check resistance of speed control vent solenoid control circuit between speed control servo 4-pin connector and ground. See SPEED CONTROL SERVO CONNECTOR WIRE IDENTIFICATION  table. If resistance is less than 5 ohms, repair short to ground on speed control vent solenoid control circuit. Perform TEST VER-4A: SPEED CONTROL VERIFICATION . If resistance is 5 ohms or more, replace speed control servo. Perform TEST VER-4A: SPEED CONTROL VERIFICATION .
SPEED CONTROL SERVO CONNECTOR WIRE IDENTIFICATION

Application Wire Color
Brake Switch Output Circuit Dark Blue/Red
Vacuum Solenoid Control Circuit Tan/Red
Vent Solenoid Control Circuit Light Green/White
Ground Black
BRAKE SWITCH CONNECTOR WIRE IDENTIFICATION

Application Wire Color
Speed Control Power Supply Circuit Yellow/Red
Brake Switch Output Circuit Dark Blue/Red
PCM CONNECTOR WIRE IDENTIFICATION

Application Wire Color
PCM Terminal No. 56
Speed Control Vacuum Solenoid Control Circuit Tan/Red
PCM Terminal No. 80
Speed Control Vent Solenoid Control Circuit Light Green/Red
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